FM / perl5

/usr/share/perl5

Name	Size	Mode	Actions
Attribute/	-	0755	rm
B/	-	0755	rm
Class/	-	0755	rm
Compress/	-	0755	rm
Config/	-	0755	rm
CPAN/	-	0755	rm
DBM_Filter/	-	0755	rm
Devel/	-	0755	rm
encoding/	-	0755	rm
ExtUtils/	-	0755	rm
File/	-	0755	rm
Getopt/	-	0755	rm
I18N/	-	0755	rm
IO/	-	0755	rm
IPC/	-	0755	rm
Locale/	-	0755	rm
Math/	-	0755	rm
Memoize/	-	0755	rm
Module/	-	0755	rm
Net/	-	0755	rm
overload/	-	0755	rm
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pod/	-	0755	rm
Search/	-	0755	rm
Term/	-	0755	rm
Text/	-	0755	rm
Thread/	-	0755	rm
Tie/	-	0755	rm
Time/	-	0755	rm
Unicode/	-	0755	rm
unicore/	-	0755	rm
URI/	-	0755	rm
User/	-	0755	rm
vendor_perl/	-	0755	rm
warnings/	-	0755	rm
AnyDBM_File.pm	2618	0644	edit dl rm
AutoLoader.pm	15797	0644	edit dl rm
AutoSplit.pm	19637	0644	edit dl rm
autouse.pm	4238	0644	edit dl rm
base.pm	10980	0644	edit dl rm
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blib.pm	2086	0644	edit dl rm
bytes.pm	3754	0644	edit dl rm
bytes_heavy.pl	758	0644	edit dl rm
charnames.pm	20867	0644	edit dl rm
CORE.pod	3188	0644	edit dl rm
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deprecate.pm	3079	0644	edit dl rm
diagnostics.pm	19038	0644	edit dl rm
DirHandle.pm	1556	0644	edit dl rm
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dumpvar.pl	15555	0644	edit dl rm
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fields.pm	9489	0644	edit dl rm
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FileHandle.pm	6784	0644	edit dl rm
filetest.pm	4003	0644	edit dl rm
FindBin.pm	4561	0644	edit dl rm
if.pm	3340	0644	edit dl rm
integer.pm	3254	0644	edit dl rm
Internals.pod	2576	0644	edit dl rm
less.pm	3204	0644	edit dl rm
locale.pm	4855	0644	edit dl rm
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meta_notation.pm	2117	0644	edit dl rm
NEXT.pm	18846	0644	edit dl rm
open.pm	8021	0644	edit dl rm
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overloading.pm	1808	0644	edit dl rm
perl5db.pl	316420	0644	edit dl rm
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Safe.pm	25082	0644	edit dl rm
SelectSaver.pm	1076	0644	edit dl rm
SelfLoader.pm	17692	0644	edit dl rm
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sort.pm	6081	0644	edit dl rm
strict.pm	4738	0644	edit dl rm
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Test.pm	30057	0644	edit dl rm
Thread.pm	8287	0644	edit dl rm
UNIVERSAL.pm	6594	0644	edit dl rm
URI.pm	34790	0644	edit dl rm
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vars.pm	2414	0644	edit dl rm
vmsish.pm	4313	0644	edit dl rm
warnings.pm	44756	0644	edit dl rm
XSLoader.pm	11267	0644	edit dl rm
_charnames.pm	33166	0644	edit dl rm

Edit: /usr/share/perl5/integer.pm (3254B)

package integer;

our $VERSION = '1.01';

=head1 NAME

integer - Perl pragma to use integer arithmetic instead of floating point

=head1 SYNOPSIS

use integer;
    $x = 10/3;
    # $x is now 3, not 3.33333333333333333

=head1 DESCRIPTION

This tells the compiler to use integer operations from here to the end
of the enclosing BLOCK.  On many machines, this doesn't matter a great
deal for most computations, but on those without floating point
hardware, it can make a big difference in performance.

Note that this only affects how most of the arithmetic and relational
B<operators> handle their operands and results, and B<not> how all
numbers everywhere are treated.  Specifically, C<use integer;> has the
effect that before computing the results of the arithmetic operators
(+, -, *, /, %, +=, -=, *=, /=, %=, and unary minus), the comparison
operators (<, <=, >, >=, ==, !=, <=>), and the bitwise operators (|, &,
^, <<, >>, |=, &=, ^=, <<=, >>=), the operands have their fractional
portions truncated (or floored), and the result will have its
fractional portion truncated as well.  In addition, the range of
operands and results is restricted to that of familiar two's complement
integers, i.e., -(2**31) .. (2**31-1) on 32-bit architectures, and
-(2**63) .. (2**63-1) on 64-bit architectures.  For example, this code

use integer;
    $x = 5.8;
    $y = 2.5;
    $z = 2.7;
    $a = 2**31 - 1;  # Largest positive integer on 32-bit machines
    $, = ", ";
    print $x, -$x, $x+$y, $x-$y, $x/$y, $x*$y, $y==$z, $a, $a+1;

will print:  5.8, -5, 7, 3, 2, 10, 1, 2147483647, -2147483648

Note that $x is still printed as having its true non-integer value of
5.8 since it wasn't operated on.  And note too the wrap-around from the
largest positive integer to the largest negative one.   Also, arguments
passed to functions and the values returned by them are B<not> affected
by C<use integer;>.  E.g.,

srand(1.5);
    $, = ", ";
    print sin(.5), cos(.5), atan2(1,2), sqrt(2), rand(10);

will give the same result with or without C<use integer;>  The power
operator C<**> is also not affected, so that 2 ** .5 is always the
square root of 2.  Now, it so happens that the pre- and post- increment
and decrement operators, ++ and --, are not affected by C<use integer;>
either.  Some may rightly consider this to be a bug -- but at least it's
a long-standing one.

Finally, C<use integer;> also has an additional affect on the bitwise
operators.  Normally, the operands and results are treated as
B<unsigned> integers, but with C<use integer;> the operands and results
are B<signed>.  This means, among other things, that ~0 is -1, and -2 &
-5 is -6.

Internally, native integer arithmetic (as provided by your C compiler)
is used.  This means that Perl's own semantics for arithmetic
operations may not be preserved.  One common source of trouble is the
modulus of negative numbers, which Perl does one way, but your hardware
may do another.

% perl -le 'print (4 % -3)'
    -2
    % perl -Minteger -le 'print (4 % -3)'
    1

See L<perlmodlib/"Pragmatic Modules">, L<perlop/"Integer Arithmetic">

=cut

$integer::hint_bits = 0x1;

sub import {
    $^H |= $integer::hint_bits;
}

sub unimport {
    $^H &= ~$integer::hint_bits;
}

package integer; our $VERSION = '1.01'; =head1 NAME integer - Perl pragma to use integer arithmetic instead of floating point =head1 SYNOPSIS use integer; $x = 10/3; # $x is now 3, not 3.33333333333333333 =head1 DESCRIPTION This tells the compiler to use integer operations from here to the end of the enclosing BLOCK. On many machines, this doesn't matter a great deal for most computations, but on those without floating point hardware, it can make a big difference in performance. Note that this only affects how most of the arithmetic and relational B handle their operands and results, and B how all numbers everywhere are treated. Specifically, C has the effect that before computing the results of the arithmetic operators (+, -, *, /, %, +=, -=, *=, /=, %=, and unary minus), the comparison operators (<, <=, >, >=, ==, !=, <=>), and the bitwise operators (|, &, ^, <<, >>, |=, &=, ^=, <<=, >>=), the operands have their fractional portions truncated (or floored), and the result will have its fractional portion truncated as well. In addition, the range of operands and results is restricted to that of familiar two's complement integers, i.e., -(2**31) .. (2**31-1) on 32-bit architectures, and -(2**63) .. (2**63-1) on 64-bit architectures. For example, this code use integer; $x = 5.8; $y = 2.5; $z = 2.7; $a = 2**31 - 1; # Largest positive integer on 32-bit machines $, = ", "; print $x, -$x, $x+$y, $x-$y, $x/$y, $x*$y, $y==$z, $a, $a+1; will print: 5.8, -5, 7, 3, 2, 10, 1, 2147483647, -2147483648 Note that $x is still printed as having its true non-integer value of 5.8 since it wasn't operated on. And note too the wrap-around from the largest positive integer to the largest negative one. Also, arguments passed to functions and the values returned by them are B affected by C. E.g., srand(1.5); $, = ", "; print sin(.5), cos(.5), atan2(1,2), sqrt(2), rand(10); will give the same result with or without C The power operator C<**> is also not affected, so that 2 ** .5 is always the square root of 2. Now, it so happens that the pre- and post- increment and decrement operators, ++ and --, are not affected by C either. Some may rightly consider this to be a bug -- but at least it's a long-standing one. Finally, C also has an additional affect on the bitwise operators. Normally, the operands and results are treated as B integers, but with C the operands and results are B. This means, among other things, that ~0 is -1, and -2 & -5 is -6. Internally, native integer arithmetic (as provided by your C compiler) is used. This means that Perl's own semantics for arithmetic operations may not be preserved. One common source of trouble is the modulus of negative numbers, which Perl does one way, but your hardware may do another. % perl -le 'print (4 % -3)' -2 % perl -Minteger -le 'print (4 % -3)' 1 See L, L =cut $integer::hint_bits = 0x1; sub import { $^H |= $integer::hint_bits; } sub unimport { $^H &= ~$integer::hint_bits; } 1;